Incentives for lower water usage?

[Andreas W.]

I own a condo inhabited by four unrelated individuals, which is legal in Raleigh, NC. As landlord I pay the utility bills and just don't get how each resident can use 86 gal of water daily. I was told that this is not unusual. Nevertheless, it is more than 3 times the amount used in the household I reside in, and that includes daily showers by most residents.  I was wondering if other landlords experiment with incentive models to have the tenants don't waste as much water.

[Chris Martin]

The easy answer is have the tenant pay the water bills.